Dock mounted support structures, sometimes referred to as cleats, may typically be a pair of opposite projections supported above the surface of a dock or deck. Boats are moored to docks and piers utilizing boat cleats which may be more often mounted to docks, piers, but may even be found mounted to boat decks. Conventional boat cleats normally do not provide any means of lighting and if some form of lighting is supplied, such as adjacent to the cleat, such lighting is required to be hooked up to power mains. Powering any form of lighting via the power mains will involve a power distribution network and possibly through-dock drilling either for the lighting or for the path of the power distribution cord, as any such power distribution must be kept out of the way. Maintenance is also an issue, including both the maintenance and inspection of the power distribution system, but also of maintaining the light sources. Maintaining the light sources usually involves access to the inside of a lighting device and the requirement to perform maintenance one unit at a time along the dock's edge.
Many variations of cleat structure and orientation are possible, but the usually seen boat cleats are mounted to be parallel with cantilevered arms of the cleats generally oriented in serial parallel and along the edge of a structure that provides mooring of and easy access to a boat. On long runs of dock, cleats are typically mounted parallel with and adjacent an edge of the dock where a boat is likely to be moored.
Even absent all other considerations, conventional cleats are somewhat of a necessary hazard. A typical cleat must have enough of an upward projection above the dock to enable a rope to be wrapped around it multiple times (typically with the last few loops ending in a criss-cross fashion). Mounting a cleat either partially or fully below deck level would be difficult and impractical. As a result the necessary upward projection is a stumbling and tripping hazard, especially in low light. This hazard is particularly severe at the intersection between dock and boat, at positions where it is usual to board and leave the vessel.
Further, even ignoring the pedestrian factor, boat operations can require a quick tie-up to the dock, particularly when the crew doesn't carry personal lighting, or when flashlight handling would impair the ability of crew members to handle the lines. This circumstance can be especially challenging where a dock area lacks lighting is approached at night. Even if the cleats cannot be seen, they must be located in order to be engaged with lines. Where not viewable, and in absolute darkness the crew may toss a line blindly at the dock hoping to snag a cleat or some other damage resistant structure.